Thin-walled, mesoporous and nitrogen-doped hollow carbon spheres using ionic liquids as precursors

Nitrogen-doped hollow carbon spheres with uniform and tunable morphology can be facilely synthesized by the monodisperse silica-template carbonization followed by hydrofluoric acid etching. The hollow carbon spheres containing 3.2 wt% of nitrogen have a thin wall of 5–12 nm and mesoporous shell structure.